What is the reason behind sudden weight increase? My weight suddenly got increased by 10kgs in 1 mth

Water? Fat? Muscle? The things that can cause rapid weight gain in a person (10kg = 22lb) in just one month include overeating (increased fat), water retention (some serious heart, liver, or kidney diseases can cause it), muscle growth (less likely), pregnancy, a fast growing tumor, hormonal disorders, etc... A doctor can evaluate and order tests if needed, to find the reason for the weight gain.